Custom elastomeric earmold with secondary material infusion

ABSTRACT

A method of making a mold, the mold having an interior cavity for containing a first material and a second material, wherein the mold comprises a first port configured to receive the first material, a second port configured to receive the second material, and a first channel for directing the second material to within the first material, the method includes: determining an electronic file having data representing a shape of an ear; processing the electronic file to create an electronic model of the mold, the electronic model of the mold having sprue features; and creating the mold based on the electronic model of the mold.

RELATED APPLICATION DATA

This application is a continuation application of U.S. patentapplication Ser. No. 15/496,773 filed on Apr. 25, 2017, pending, whichclaims priority to and the benefit of U.S. Provisional PatentApplication No. 62/327,723, filed on Apr. 26, 2016, lapsed, the entiredisclosures of all of the above applications are expressly incorporatedby reference herein.

FIELD

This disclosure relates to systems and methods for making a hearingdevice components, and more specifically, to systems and methods formaking earmolds.

BACKGROUND

Various techniques may be employed to design and fabricate customearmold and hearing aid shell. For examples, digital data processing and3D Printing (rapid prototyping) have been utilized to make customearmolds. These techniques provide the ability to add sophisticatedfeatures to a custom product while maintaining a reasonable, machinebased fabrication.

Many sound producing (hearing aids and earphones) and hearing protective(earplugs and musician plugs) devices require that 1) that the deviceprovides a good acoustic seal which is important for device performanceand sound quality, and 2) that the device fits comfortably in the ear.There are many concepts for achieving this through the use of a varietyof materials including elastomers and foams in a variety of shapes,sizes and processes.

However, in all examples of composite devices the elastomeric part andthe foam part are added as separate items with the foam piece added tothe elastomer in a secondary operation, or are pumped into an inflatablecontainer.

SUMMARY

A new process for making custom elastomeric earmoulds used in bothactive sound processing units (hearing aids, earphones) and passivedevices (earplugs, swim plugs) is described herein. The process createsa product that is made from soft, biocompatible material such assilicone or urethane that is infused with compatible, compressible foam,or other soft materials, in order to achieve softness and compliance inspecific areas on the earmold. The result is an earmold with localizedsoftness and compliancy that surpasses previous art by achieving higherdegrees of comfort, improved acoustic seal, and by allowing a deeper fitin the ear canal can prevent occlusion effects.

The combination of the material and the two design concepts accomplishesone of more of the followings: 1) It creates a product with excellentretention in the ear due to the outer ear customization; 2) It creates aproduct with improved compliance to move as the ear canal moves,improved comfort, increased flexibility, excellent acoustic seal and adeeper seal resulting in reduced occlusion in the ear canal. Thisimprovement is the result of the foam infused areas that are softer,more compressible, but springier (e.g., more deformable, more elastic,etc.) than a solid elastomeric material and, therefore, becomes moreaccommodating to the dynamics of the canal when compared to full custommolds. The light spring force of the foam material provides an improvedacoustic seal without discomfort; 3) It creates a comfortable productwith improved and deeper acoustic seal over a full custom product as thesilicone/silicone foam combination provides a compliant seal that doesnot break when the wearer moves his head or jaw.

In some embodiments, the product may be created using a digitalprocesses common to the manufacture of hearing aid products. In thiscase, the process is used to make a one-time mold for casting siliconeor urethane elastomers, but in addition to injecting the primaryelastomer, an additional process step is performed to add a secondaryinterior material that is fully contained within the primary elastomer.The process takes advantage of the surface tension effect of the primarymaterial to stay adhered to the interior surface of the exterior wallsof the mold. This allows the secondary material to occupy the interiorwithout displacing the base elastomer from the exterior.

Embodiments described herein will improve the performance of any in-earproduct including, but not exclusive to: 1) hearing aids, 2) hearingprotection, and 3) custom earphones.

Embodiments described herein involve use of a custom mold for the ear.In some embodiments, the custom mold has a custom portion confined tothe outer ear and entry to the canal only. In other embodiments, thecustom mold may have non-custom portion(s), and/or may not be confinedto the outer ear and entry to the canal. For example, in otherembodiments, the custom mold may extend to other parts of the user'sear, such as an outer part of the ear cannal and/or an inner part of theear canal. The mold is made from injecting an elastomeric material intoa one use injection made in a 3D printing process. Any portion of themold can be enhanced through the infusion of a secondary material whichdisplaces the original material from only the interior of the mold dueto the surface tension characteristics of the primary elastomericmaterial which keep the primary material adhered to the injection moldsurface.

Foam has an advantage over monolithic or solid materials in anyapplication requiring compliance and comfort of an item in contact witha human. Foam is commonly used to enhance comfort in products rangingfrom furniture to shoes to helmets. Foam has also been used in earplugsfor decades, but generally in pre-molded form. Foam has also beenapplied to earmolds to improve comfort and also to improve performanceby providing a better acoustic seal.

However foam has some limitations in the custom earmold applications dueto problems associated with production (short working times, limitationof material selection) and customer use associated with insertion (thefoam is too flaccid to allow insertion), cleanliness (foams allowforeign material to become trapped in the foam cells) and strength (thetear strength of foam limits its ability to be removed from the ear ifthe mold fits too tight or is handled too roughly). Due to theselimitations, most custom soft earmoulds are made from monolithicelastomers (silicone, PVC and urethane) rather than foam.

In some cases, one may attempt to provide a combination of silicone andfoam or urethane and foam in order to take advantage of the beneficialproperties of each. For example, the foam may be added as a separatepiece of the mold using some assembly process. In non-custom ear tipapplications, foam may be used by itself or combined with otherpremolded items to form a more complex device.

Embodiments described herein provide an improved method for combiningfoam and silicone in a custom application by using the castingtechniques provided by 3D printing. A 3D mold can be used as a singleuse injection mold for a variety of material. At least one embodimentuses the basic concept of the one shot mold, but uses the concept of asecondary infusion of material to create a composite mold of both theprimary material injected in the mold and the secondary materialinjected in the mold. The process also utilizes the chemicalcharacteristic of surface tension to maintain the primary material asthe “outer” skin or layer of the final device, while limiting thesecondary material to the interior of the device. In this way the outerlayer maintains the advantages of the primary material while theinterior maintains the advantages of the secondary material.

The combination of materials is unlimited as long as they are chemicallycompatible and can be injected into a 3D printed mold. By means ofnon-limiting examples, some combinations are:

Primary material: silicone; Secondary material: silicone foam

Primary material: silicone of hardness A; Secondary material: siliconeof a different hardness (e.g., lower hardness)

Primary material: silicone; Secondary material: silicone gel

Primary material: silicone; Secondary material: silicone of anothercolor

Primary material: urethane; Secondary material: urethane foam

Primary material: urethane of hardness A; Secondary material: urethaneof a different hardness (e.g., lower hardness)

Primary material: urethane; Secondary material: urethane gel

Primary material: urethane; Secondary material: urethane of anothercolor

Primary material: urethane, or urethane and urethane foam.

Primary material: silicone; Secondary material: air

Primary material: silicone; Secondary material: a compatible liquid.

Primary material: silicone; Secondary material: urethane

A composite mold has the advantage of combining the desirable propertiesof both materials. For example, the silicone (primary) and silicone foam(secondary) composite has the advantage of the softness and complianceof the foam, but has the stiffness, strength and chemical stability ofsilicone. This results in an earmold of superior performance since it isvery comfortable due to the foam, can go deep in the ear because of thiscomfort, will provide a better acoustic seal due to the compliance ofthe foam, but due to the stiffness of the silicone outer layer theearmold can be inserted easily, provides a biologically compatiblesurface, is easily cleaned and provides durable performance regardingtear strength and chemical resistance.

The composite earmold accomplishes one or more of the followings: 1) Itachieves a better acoustic seal than a tight-fitting, full custom canaldue to the improved compliance (softness) and shape changing abilitiesof foam; 2) It improves the comfort of the device for the same reasonsof improved compliance and shape changing while forgiving incomplete earimpressions; 3) The composite mold can go deeper into the canal due tothe improved softness and flexibility which has the advantages ofreducing the occlusion effect; 4) It achieves lower noise levelsassociated with jaw movement and leaks associated with the continualloss and regain of an acoustic seal experienced using a tight fitting,monolithic material.

Another advantage of the molding process that entraps the secondarymaterial on the interior of the mold is the allowance of liquids or gelsas the secondary material. This allows the use of superior acousticdampening caused by a variety of material choices.

The custom injection mold and casting may be used/performed in variousprocesses, such as digital data processing, 3D Printing (rapidprototyping), etc.

In this case the shape of a person's ear is acquired through theinjection of silicone into the ear and ear canal, or the outer ear andcanal entry areas are scanned with a laser or white light scanner. Thescanned image is used to fashion, or sculpt, the final shape of theproduct, and to add predesigned features to the mold that are mergedinto the digital image of the mold. A digital file of the final productdesign is then output to a 3D Rapid Prototyping/Manufacturing machine.In this process the object that is made on the 3D printer is aninjection mold which is then filled with silicone (Martin). Once thesilicone cures, the outer “shell” of the mold is cracked open andremoved to reveal the silicone mold on the inside.

In some embodiments, the image of a person's ear may be captured, and asoftware may be provided to design the mold. In some embodiments,objects within the software may be used to add complexity to theinjection mold and earmold design. The one unique object that is addedto the earmold design is the injection mold sprue system: 1) apre-designed shape which is chosen and located to optimize the amountand position of the secondary material, this is usually in the canalarea but can also be in the outer ear area where the ear moves or ispressed upon when the wearer rests one side of the head against asurface.

Embodiments described herein involve a secondary casting operation whichinfuses a second material (e.g., foam) into the interior of theelastomeric casting. Accordingly, the elastomeric composite system andtechnique described herein are unique in that the delivery of the secondmaterial (e.g., foam) is an integral part of casting process.

In some cases, custom elastomeric molds may be casted using a single use3D printed mold. Embodiments described herein utilize this process, butmoves beyond that by not only creating a specialized exterior shape, butby also creating a specialized interior made from compatible foam.

In some embodiments, the process makes use of the surface tensioninvolved in the elastomer casting process. When an elastomer is injectedinto a 3D printed one-shot injection mold, the surface tension of theoriginal, or primary, material causes the elastomer to adhere to thesurface of the mold. When any secondary material (such as anotherelastomer, air, water, other liquids, pastes or foam) possessing thecharacteristic of fluidity is injected into the mold, it cannot displacethe original material from the interior surface of the mold. Rather, itcan only displace the original primary material from the interior of themold. This means that the original elastomer will remain along theinterior surface of the mold and will form the outer “skin” or “layer”of the final device, while the secondary material will form the interiorof the device.

There is a variety of process controls available that provide forcontrol of both the location and amount of the residual primary materialand the secondary infused material.

One process control is the timing of the primary material curing and thesecondary material infusion. If the curing of the primary material istime dependent, then the thickness of the outer layer of the primarymaterial may be controlled by time. This is because the curing of theprimary material, if it is a two-part catalyst curing system, is afunction of time. The same would be accomplished by heat exposure with aheat dependent primary material.

Another process control is the use of specialized sprues and vents inthe injection molding process. Placement and shape of sprues and ventscontrols the injection process and determines the location and volume ofeach material during injection.

In some embodiments, an interior portion of the primary material may beevacuated before the secondary material is placed inside the primarymaterial. In such cases, another process control may be the evacuationof the primary material before the infusion of the secondary material.The primary material may be removed by using pressurized air or liquid,such as water, that acts as a temporary displacement of the primarymaterial prior to the infusion of the secondary material into theinterior cavity of the primary material.

An apparatus for forming a component for a hearing device, the componentcomprising an earpiece having a housing, the housing comprising a wallmade from a first material, wherein the wall of the housing comprises asecond material surrounded by the first material, the apparatusincludes: a mold having an interior cavity for containing the firstmaterial and the second material; wherein the mold comprises a firstport configured to receive the first material; wherein the moldcomprises a second port configured to receive the second material, and afirst channel for directing the second material to within the firstmaterial.

Optionally, the mold comprises a single-use mold.

Optionally, the apparatus further includes a first source of the firstmaterial.

Optionally, the first material comprises silicone or urethane.

Optionally, the apparatus further includes a second source of the secondmaterial.

Optionally, the mold also comprises a second channel for directing thesecond material to within the first material.

Optionally, the second material comprises silicone gel, silicone foam,urethane gel, or urethane foam.

Optionally, the apparatus further includes a source of liquid or air fordisplacing some of the first material after the first material isdelivered inside the mold.

Optionally, the mold comprises a custom mold.

A component for a hearing device includes: an earpiece having a housing,wherein the housing comprises a wall made from a first material; whereinthe wall of the housing comprises a second material surrounded by thefirst material.

Optionally, the housing comprises a channel, and wherein the wallsurrounds the channel.

Optionally, the earpiece comprises a custom shell.

Optionally, the second material is configured to improve a bass effectassociated with the hearing device.

Optionally, the second material is configured to provide an acousticseal by attenuating external sounds.

Optionally, the second material is configured to reduce an occlusioneffect associated with the hearing device.

Optionally, the first material comprises first silicone.

Optionally, the second material comprises second silicone different fromthe first silicone.

Optionally, the first silicone has a first hardness, and the secondsilicone has a second hardness different from the first hardness.

Optionally, the second silicone comprises silicone gel.

Optionally, the second silicone comprises silicone foam.

Optionally, the first material comprises first urethane.

Optionally, the second material comprises second urethane different fromthe first urethane.

Optionally, the first urethane has a first hardness, and the secondurethane has a second hardness different from the first hardness.

Optionally, the second urethane comprises urethane gel.

Optionally, the second urethane comprises urethane foam.

Optionally, the second material comprises liquid.

Optionally, the second material comprises foam.

Optionally, the second material comprises air.

A method of making a mold, the mold having an interior cavity forcontaining a first material and a second material, wherein the moldcomprises a first port configured to receive the first material, asecond port configured to receive the second material, and a firstchannel for directing the second material to within the first material,the method includes: determining an electronic file having datarepresenting a shape of an ear; processing the electronic file to createan electronic model of the mold, the electronic model of the mold havingsprue features; and creating the mold based on the electronic model ofthe mold.

Optionally, the electronic model comprises a CAD model.

Optionally, the data represents a shape of a concha, an outer ear canal,and an inner ear canal.

Optionally, the mold is created using a 3D printer.

Optionally, the sprue features comprise a first sprue featurerepresenting a first sprue for delivering the first material.

Optionally, the sprue features also comprise a second sprue featurerepresenting a second sprue for delivering the second material.

A method of making a component of a hearing device using the mold, themethod includes: injecting a first material into the mold; and injectinga second material into the mold so that the second material issurrounded by the first material; wherein the first material and thesecond material form parts of the component.

Optionally, the method further includes breaking the mold to remove thecomponent.

Optionally, the method further includes removing an interior of thefirst material to create a cavity within the first material, wherein thesecond material is injected into the cavity within the first material.

Optionally, the act of removing comprises delivering liquid or air intothe first material.

Optionally, the component comprises an earpiece.

An apparatus for forming a first component for a first hearing device,the first component comprising an earpiece having a housing, the housingcomprising a wall made from a first material, wherein the wall of thehousing comprises a second material surrounded by the first material,the apparatus includes: a mold having a first interior cavity forcontaining the first material and the second material, wherein the moldcomprises a first port configured to receive the first material; and afirst source of the second material for delivering the second materialinto the first interior cavity so that the second material is within thefirst material.

Optionally, the first source of the second material comprises a firstsyringe.

Optionally, the apparatus is also for forming a second component for asecond hearing device, the apparatus comprising a second interior cavityand a second source of the second material for delivering the secondmaterial into the second interior cavity.

Optionally, the first source comprises a first syringe, and the secondsource comprises a second syringe.

Other and further aspects and features will be evident from reading thefollowing detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate the design and utility of embodiments, in whichsimilar elements are referred to by common reference numerals. In orderto better appreciate how advantages and objects are obtained, a moreparticular description of the embodiments will be described withreference to the accompanying drawings. Understanding that thesedrawings depict only exemplary embodiments and are not therefore to beconsidered limiting in the scope of the claimed invention.

FIG. 1 illustrates a method of making a component of a hearing device.

FIG. 2 illustrates another method of making a component of a hearingdevice, which includes using a medium for displacement of a primarymaterial before adding a secondary material.

FIG. 3 illustrates an ear impression captured with digital 3D scanning.This is the starting point image for creating the component of thehearing device. This figure shows an anterior view (right) and aposterior view (left) of the canal/inner ear.

FIG. 4 illustrates sprues for injecting primary material and secondarymaterial into a mold.

FIG. 5 illustrates a single use injection mold, having two injectionports to allow the creation of a composite mold from two differentmaterials such as soft and hard, or different colors.

FIG. 6 illustrates a cross sectional view of the injection mold of FIG.5, configured to create an earmold, particularly showing how the spruesare configured to introduce material into the single use injection mold.

FIG. 7 illustrates an earmold inside of the single use injection moldduring a “demolding” step of removing the earmold from the single useinjection mold.

FIG. 8 illustrates an example of a device (e.g., a component of ahearing device) made from a primary material of either silicone orsilicone elastomer that is infused with an interior of a secondarymaterial such as foam, gel, or a elastomer of a different hardness orcharacteristic from the primary material.

FIG. 9 illustrates the device of FIG. 8 as shown from the inferior view(left) and with a cross section through the anterior view to show thelocation of the primary and secondary materials. The primary materialremains in areas where it was in contact with the injection mold wall,but is displaced in specific areas by the secondary material.

FIG. 10 illustrates the device of FIG. 8 as shown from the end of theear canal (left) with a cross section through the canal view to show thelocation of the primary and secondary materials. The primary materialremains in areas where it was in contact with the injection mold wall,but is displaced in specific areas by the secondary material.

FIG. 11 illustrates the device of FIG. 8 as shown from the end of theear canal (left) with a cross section through the canal view to show thelocation of the primary and secondary materials.

FIG. 12 illustrates another example of a single use injection mold and acutaway section of the single use injection mold.

FIG. 13 illustrates the injection mold of FIG. 12 filled with a primarymaterial.

FIG. 14 illustrates the injection mold of FIG. 12 filled with theprimary material, and the interior area of the primary material has beendisplaced with air or water to create a hollow area in the primarymaterial.

FIG. 15 illustrates the injection mold of FIG. 12 filled with theevacuated primary material forming a thin wall against the interiorsurface of the injection mold. The evacuated interior is filled with asecondary material to form a compliant interior.

FIG. 16 illustrates another apparatus for forming one or more componentsof one or more hearing devices.

DESCRIPTION OF THE EMBODIMENTS

Various embodiments are described hereinafter with reference to thefigures. It should be noted that the figures may or may not be drawn toscale and that elements of similar structures or functions arerepresented by like reference numerals throughout the figures. It shouldalso be noted that the figures are only intended to facilitate thedescription of the embodiments. They are not intended as an exhaustivedescription of the claimed invention or as a limitation on the scope ofthe claimed invention. In addition, an illustrated embodiment needs nothave all the aspects or advantages of the invention shown. An aspect oran advantage described in conjunction with a particular embodiment isnot necessarily limited to that embodiment and can be practiced in anyother embodiments even if not so illustrated or if not so explicitlydescribed.

FIG. 1 illustrates a method 100 of creating a component of a hearingdevice. In the illustrated example, the component is a earpiece of thehearing device. However, in other embodiments, the component may be anyother part of the hearing device. By means of non-limiting examples, thehearing device may be a hearing aid (such as in-the-ear hearing aid,completely-in-canal hearing aid, behind-the-ear hearing aid, etc.), anearphone, an earplug, an eardome, an earpiece for testing probe, an earprotection, etc.

As shown in the figure, first, a digital scan of an ear is created (item102). Various techniques may be employed to obtain the digital scan. Forexample, a light-based scanning probe may be used to scan the ear. Asanother example, ultrasound-based scanning probe may be used to scan theear. Handheld scanners known in the art may be employed in differentembodiments. Also, an ear impression (e.g., a direct material cast ofthe ear cavity and shape) may be obtained, and the ear impression maythen be scanned to create the digital scan for the ear. The digital scanmay be embodied in a form of a digital file having data that representsfeatures of the ear. The features of the ear may include interior cavityof the human ear canal and the outer ear areas. Also, in someembodiments, the data in the digital file may represent a shape of aconcha, an outer ear canal, and an inner ear canal. In otherembodiments, other techniques may be employed to create the digitalfile, which may or may not involve scanning of the ear.

Next, a computer-aid-design (CAD) software or tool is used to create amodel of the ear based on the digital file (item 104). For example, thedigital file may be converted into a CAD format to obtain a CAD model ofthe ear. The CAD tool may be used to modify the model of the ear. Forexample, certain undesirable features of the model may be deleted,certain parts of the model may be adjusted in shape and/or dimension,etc. The CAD software or tool may be any design tool that can be used inproduct design. For example, in some embodiments, the design tool may beeSculpting. In one implementation, the digital file representingfeatures of the ear may be loaded into software (e.g., eSculpting)specifically configured for creating earmold products from digitallyscanned images.

Next, sprue features are added to the CAD model of the ear to obtain amodified model of the ear (item 106). In some embodiments, the spruefeatures include a first sprue feature representing a first sprue fordelivering a first material into the injection mold to be created, and asecond sprue feature representing a second sprue for delivering a secondmaterial into the injection mold to be created. In other embodiments,the sprue features may include more than two sprue features. In someembodiments, the first sprue may include a cavity for containing thefirst material, and one or more channels or tubes for delivering thefirst material into the cavity of the injection mold to be created.Similarly, the second sprue may include a cavity for containing thesecond material, and one or more channels or tubes for delivering thesecond material into the cavity of the injection mold to be created. Insome embodiments, item 106 is not required.

Next, the design tool may be used to obtain a model of the injectionmold to be created (item 108). This injection mold model may be adigital representation of the injection mold. In some embodiments, thedesign tool may be configured to use the ear model or the modified earmodel to create the injection mold model. Such may be accomplished bycreating an offset from the ear model or the model of the device (i.e.,the component of the hearing device) that is desired to be created. Thisresults in a model of a hollow injection mold with the interior havingthe shape of the desired component to be created. In the illustratedembodiments, the created model of the injection mold also includespredesigned features of the sprues for both the first (primary) materialand the second (secondary) material. In some embodiments, the spruesfeatures are incorporated in item 106. In other embodiments, thefeatures of the sprues may be inserted to the injection mold model initem 108 when the injection mold model is being created. In such cases,item 106 may not be required. In further embodiments, part(s) of thesprues features may be inserted in item 106, and other part(s) of thesprues features may be inserted in item 108.

In one implementation, eSculpting may be used to alter the shape of theear model to create the shape of the injection mold model. The injectionmold model includes objects for creating the sprues for the firstmaterial and the sprue for the second material.

Next, an injection mold is created based on the injection mold model(item 110). In the illustrated example, the injection mold is a singleuse injection mold. In such cases, after the component of the hearingdevice is created using the injection mold, the injection mold isdestroyed in order to retrieve the created component. In otherembodiments, the injection mold may not be a single use injection mold.For example, the injection mold may instead have multiple componentsthat can be detachably coupled to each other. In such cases, after thecomponent of the hearing device is made, the mold components may bedetached from each other, and may then be reassembled to create theinjection mold repeatedly. Also, in some embodiments, item 108 may beperformed using a 3D printer, which receives the electronic filerepresenting the injection mold, and creates the injection mold based onthe received electronic file. The 3D printing process may be performedby any of a variety of 3D printers on the market today using a varietyof materials. In some embodiments, the injection mold material may bechemically compatible with the material (e.g., first material) used tomake the component of the hearing device.

After the injection mold is made, the injection mold may then be used tocreate the component of the hearing device. As shown in the figure, afirst material (primary material) is first placed (e.g., injected) intothe injection mold (item 112). The primary material may be an elastomer,or any of other types of materials that may be suitable for thecomponent being created. By means of non-limiting examples, the firstmaterial may be silicone, urethane, etc. In the illustrated embodiments,because the injection mold has a first sprue configured to deliver thefirst material, the first sprue may be used to deliver the firstmaterial to an interior cavity of the injection mold. The first materialmay be injected into the injection mold until the entire interiorsurface, or substantially the entire interior surface, of the injectionmold is covered by the first material.

Next, a second material (secondary material) is placed (e.g., injected)into the injection mold (item 114). The second material may be liquid,gel, foam, or any of other types of materials. By means of non-limitingexamples, the second material may be silicone gel, silicone foam,urethane gel, urethane form, etc. In some embodiments, the secondmaterial has a characteristic (e.g., hardness, color, etc.) that isdifferent from the characteristic of the first material. In theillustrated embodiments, because the injection mold has a second sprueconfigured to deliver the second material, the second sprue may be usedto deliver the second material inside the injection mold.

In the illustrated embodiments, due to surface tension effect, the firstmaterial will adhere to the interior surface of the outer walls of theinjection mold, while the second material is delivered into theinjection mold. This allows the secondary material to occupy theinterior of the injection mold without displacing the first materialfrom the exterior or outer part of the injection mold cavity along thewalls of the injection mold cavity. This allows the primary material toform the “outer” skin or layer of the component, while limiting thesecondary material to the interior of the component. As a result, in thecreated component, the outer layer will have the advantages and featuresprovided by the first material, while the interior part of the componentwill have the advantages and features provided by the second material.

In the illustrated embodiments, the second material is injected into theinjection mold using the sprue(s) intended for the second material. Thisplaces the second material in specific locations chosen to optimize theperformance of the injection mold and helps to balance the flow of thematerial into specific areas of the injection mold. In some cases, theremay be multiple sprues located at different parts of the injection moldfor delivering the second material into the injection mold. In someembodiments, the timing of injecting the second material via the one ormore sprues, and/or injection pressure may be selected to affect theinjection results. Also, in some embodiments, the amount of time allowedbetween the first and the second injections and/or a temperature of theprocess may affect the thickness of component part formed by the firstmaterial if the first material's curing reaction is time or temperaturedependent.

The first and second materials are then cured to form the component.After the component of the hearing device is formed using the first andsecond materials, the component of the hearing device is then removedfrom the injection mold (item 116). In the illustrated example, theinjection mold is a single use injection mold, and item 116 involvesbreaking the injection mold to remove the component of the hearingdevice from the injection mold. In other embodiments, the injection moldmay include mold components that are detachably coupled to each other.In such cases, the mold components are separated from each other toremove the component of the hearing device.

Next, one or more additional processes may be performed on the componentof the hearing device (item 118). For example, extra undesirablematerial attached to the component may be removed from the component bycutting, grinding, etc. Also, the surface of the component may beprocessed to create a desirable surface for the component. In otherembodiments, item 118 is not required, and the component of the hearingdevice may be considered completed after item 116 is performed.

The component (e.g., the earmold in the example) of the hearing devicemade via the above technique has the first material located on the outerparts of the component, with the second material encased within thefirst material. In some embodiments, the first material may form a wallof an earmold, and the second material may be located in the wall andmay be surrounded by the first material (e.g., the first material mayform two opposite surfaces/layers of the wall, with the second materialbeing sandwiched between the two layers of the first material). In somecases, the wall may surrounds a channel, wherein the channel is definedby the wall. In other embodiments, the first material may form the wallof the earmold, with the second material being located within a cavityof the earmold surrounded by the first material.

It should be noted that as used in this specification, the term“surrounded” or any of other similar terms refers to an item that iscompletely enclosed by another item, or that is substantially enclosedby another item. For example, when the second material is beingdescribed as “surrounded” by the first material, the second material maybe completely enclosed by the first material, or may be substantiallyenclosed by the first material (e.g., at least 80%, 85%, 90%, 95%, or99% of the surface area of the second material may be covered by thefirst material).

FIG. 2 illustrates another method 100 of creating a component of ahearing device. The method 100 of FIG. 2 is the same as that of FIG. 1,except that the method 100 of FIG. 2 further includes item 113 that isperformed after item 112. In item 113, an interior of the first materialis removed to create a cavity within the first material, wherein thesecond material can be later injected into the cavity within the firstmaterial (in item 114). In some embodiments, the act of removing theinterior of the first material may comprise delivering liquid or airinto the first material. In one implementation, the removal of theinterior part of the first material may be accomplished by using amedium that displaces the interior portion of the first material. Themedium may be compressed air or pressurized liquid to evacuate theinterior of the first material. The second material is then injectedinto the injection mold through the sprue(s) and fills the evacuatedinterior. The method 100 of FIG. 2 achieves more displacement of thefirst material, allowing for more of the second material to be placed inthe final device interior. Time and/or injection pressure may also beused to affect the injection results.

In the above embodiments, the sprues are described as being attached tothe mold that are formed together with the mold. In other embodiments,the sprues may be separately formed from the mold, and may not beintegrally formed with the mold.

FIG. 3 illustrates an ear impression (1) captured with digital 3Dscanning. This is the starting point image for creating the component ofthe hearing device (e.g., earphone device). This figure shows ananterior view (right) and a posterior view (left) of the canal/innerear.

FIG. 4 illustrates sprues (2 & 3) for injecting primary material andsecondary material into the injection mold (4).

FIG. 5 illustrates different views of an injection mold (4) showing thetwo injection ports (2,3) to allow the creation of a composite earmoldfrom two different materials such as soft and hard, or different colors.

FIG. 6 illustrates a cross section view of the injection mold (4) ofFIG. 5 used to create the earmold (5), particularly showing how thesprues (2, 3) are used to introduce material into the injection mold(4).

FIG. 7 illustrates the earmold (5) shown inside of the injection mold(4) during the “demolding” step of removing the earmold from theinjection mold (4).

FIG. 8 illustrates the earmold (5) made from a primary material ofeither silicone or silicone elastomer that is infused with an interiorof a secondary material such as foam (6), gel, or a elastomer of adifferent hardness or characteristic from the primary.

FIG. 9 illustrates the earmold (5) as shown from the inferior view(left) and with a cross section through the anterior view to show thelocation of the primary and secondary materials (7). The primarymaterial (6) remains in areas where it was in contact with the injectionmold interior wall, but is displaced in specific areas by the secondarymaterial (7).

FIG. 10 illustrates the earmold (5) as shown from the end of the earcanal (left) with a cross section through the canal view to show thelocation of the primary (6) and secondary materials (7). The primarymaterial (6) remains in areas where it was in contact with the injectionmold interior wall, but is displaced in specific areas by the secondarymaterial (7).

FIG. 11 illustrates the earmold (5) as shown from the end of the earcanal (left) with a cross section through the canal view to show thelocation of the primary (6) and secondary (7) materials.

FIG. 12 illustrates another injection mold (4) and a cutaway section ofthe injection mold (4).

FIG. 13 illustrates the injection mold (4) of FIG. 12, filled with theprimary material (6).

FIG. 14 illustrates the injection mold (4) of FIG. 12, filled with theprimary material (6), and the interior area of the primary material (5)has been displaced with air or water to create a hollow area (8) in theprimary material (6).

FIG. 15 illustrates the injection mold (4) filled with the evacuatedprimary material (6) forming a thin wall against the side of theinjection mold (4). The evacuated interior is filled with the secondarymaterial (7) to form a compliant interior.

In some embodiments, the second material may be configured (e.g.,selected and/or positionally designed) to improve a bass effectassociated with the hearing device. Also, in some embodiments, thesecond material may be configured to provide an acoustic seal byattenuating external sounds. Furthermore, in some embodiments, thesecond material may be configured to reduce an occlusion effectassociated with the hearing device.

The above techniques for creating the earmold (5) are advantageous. Byutilizing the abilities of application specific software and 3Dprinting, the earmold (5) achieved is a sophisticated compositestructure combining a variety of materials to enhance the properties,performance and appearance of the resulting earmold (5). Also, interiorfeatures of the earmold (5) are no longer limited to a set arrangementof interior spaces. Rather, the earmold (5) has customized outer shape,and also customized arrangement of the inner characteristics.

FIG. 16 illustrates another apparatus 300 for forming one or morecomponents of one or more hearing devices.

In some embodiments, the one or more hearing devices include a firsthearing device. The one or more components include a first componentcomprising an earpiece having a housing, the housing comprising a wallmade from a first material, wherein the wall of the housing comprises asecond material surrounded by the first material. In the illustratedembodiments, the apparatus 300 includes a mold 302 having a firstinterior cavity 304 a for containing the first material and the secondmaterial, wherein the mold 302 comprises a first port configured toreceive the first material. The apparatus 300 also includes a firstsource 310 a of the second material for delivering the second materialinto the first interior cavity 304 a so that the second material iswithin the first material.

In the illustrated embodiments, the apparatus 300 is also for forming asecond component for a second hearing device. The apparatus 300 includesa second interior cavity 304 b and a second source 310 b of the secondmaterial for delivering the second material into the second interiorcavity.

In some embodiments, the first source 310 a of the second materialcomprises a first syringe. As used in this specification, the term“syringe” may refer to any fluid delivery device that includes acontainer for housing fluid.

Also, in some embodiments, the first source 310 a comprises a firstsyringe, and the second source 310 b comprises a second syringe.

In some embodiments, the cavities 304 are for forming respectivecomponents for respective hearing devices. Each cavity 304 is configuredto receive a first material, and a second material so that the secondmaterial is surrounded by the first material. In some cases, the mold302 includes multiple first ports for allowing the first material to bedelivered into the respective cavities 304. The first ports may alsoallow the second material to be delivered into the respective cavities304. Alternatively, the mold 302 may include multiple second ports forallowing the second material to be delivered into the respectivecavities. In addition, in some embodiments, the apparatus 300 mayinclude multiple syringes for simultaneously injecting the secondmaterial into the respective cavities 304. In such cases, the syringesare arranged in relative positions that correspond with the positions ofthe respective cavities 304. The syringes may be mounted to a commonpositioner, which is configured to move all of the syringessimultaneously so that the injection ends of the syringes are moved intorespective ports of the mold 302 that are in fluid communication withthe respective interior cavities 304.

It should be noted that the above techniques are not limited to creatingcustomized components for hearing devices. In other embodiments, theabove techniques may be employed to create standard components forhearing devices, or components that have both customized andnon-customized features. For example, in other embodiments, the exteriorshape of the earmold (5) may be standard, while the interiorcharacteristics are customized.

Also, the above techniques may be employed to create components for avariety of hearing devices, and not just the examples illustrated in thefigures. By means of non-limiting examples, the techniques describedherein may be employed to create components for hearing aids (such asin-the-ear hearing aids, completely-in-canal hearing aids,behind-the-ear hearing aids, etc.), earphones, earplugs, eardomes,earpieces for testing probes, ear protection, etc.

Although particular features have been shown and described, it will beunderstood that they are not intended to limit the claimed invention,and it will be made obvious to those skilled in the art that variouschanges and modifications may be made without departing from the spiritand scope of the claimed invention. The specification and drawings are,accordingly to be regarded in an illustrative rather than restrictivesense. The claimed invention is intended to cover all alternatives,modifications and equivalents.

What is claimed:
 1. A method of making a mold, the mold having an interior cavity for containing a first material and a second material, wherein the mold comprises a first port configured to receive the first material, a second port configured to receive the second material, and a first channel for directing the second material to within the first material, the method comprising: determining an electronic file having data representing a shape of an ear; processing the electronic file to create an electronic model of the mold, the electronic model of the mold having sprue features; and creating the mold based on the electronic model of the mold.
 2. The method of claim 1, wherein the electronic model comprises a CAD model.
 3. The method of claim 1, wherein the data represents a shape of a concha, an outer ear canal, and an inner ear canal.
 4. The method of claim 1, wherein the mold is created using a 3D printer.
 5. The method of claim 1, wherein the sprue features comprise a first sprue feature representing a first sprue for delivering the first material.
 6. The method of claim 5, wherein the sprue features also comprise a second sprue feature representing a second sprue for delivering the second material.
 7. The method of claim 1, wherein the mold is a custom mold.
 8. A method of making a component of a hearing device using the mold of claim 1, the method comprising: injecting a first material into the mold; and injecting a second material into the mold so that the second material is surrounded by the first material; wherein the first material and the second material form parts of the component.
 9. The method of claim 8, further comprising breaking the mold to remove the component.
 10. The method of claim 8, further comprising removing an interior of the first material to create a cavity within the first material, wherein the second material is injected into the cavity within the first material.
 11. The method of claim 10, wherein the act of removing comprises delivering liquid or air into the first material.
 12. The method of claim 8, wherein the component comprises an earpiece.
 13. The method of claim 8, wherein the first material comprises silicone or urethane.
 14. The method of claim 13, wherein the second material comprises silicone gel, silicone foam, urethane gel, or urethane foam.
 15. The method of claim 8, wherein the first material comprises first silicone, and wherein the second material comprises second silicone different from the first silicone.
 16. The method of claim 15, wherein the first silicone has a first hardness, and the second silicone has a second hardness different from the first hardness.
 17. The method of claim 15, wherein the second silicone comprises silicone gel.
 18. The method of claim 15, wherein the second silicone comprises silicone foam.
 19. The method of claim 8, wherein the second material comprises liquid.
 20. The method of claim 8, wherein the second material comprises foam.
 21. The method of claim 8, wherein the second material comprises air. 